Scarlet Caterpillar Club

Cordyceps militaris
Wednesday, July 27, 2011

           This orange fungus, sometimes called the scarlet caterpillar club, may appear similar to many other club fungi until one digs beneath the surface. This incredible ascomycete is parasitic on the larvae of moths and butterflies which pupate below the ground. While the larva is pupating underground, the mycelium of C. militaris infects and colonizes the pupa. The mycelium effectively mummifies it, keeping it alive for long enough to generate the biomass necessary to produce the fruiting body of the fungus. It then kills the larva, and uses all of its remaining energy for spore production on the club-shaped “mushroom” which protrudes above the ground.

           Above ground, this fungus appears simple enough. It is usually orange to pale-orange in color, and darker colored at the top of the fruiting body. The top of the fruiting body widens, and can appear roughened or wrinkly. This “club” can be 2-8 cm long, and around .5 cm wide. The club narrows at the base and disappears into the ground. As with many species within the genus Cordyceps, accurate identification is impossible if one does not dig under the club fungus to identify the type of insect being parasitized. All Cordyceps species parasitize some form of insect or another; some erupt from puffballs, while others parasitize living ants and produce hormones to compel them to do what the mushroom wishes before killing them.

           One typically finds C. militaris protruding from the leaf litter in the summer or fall. They are widely distributed across much of North America, but occur more densely east of the Rocky Mountains. They are also found in Europe.

           C. militaris has long been an element of traditional Chinese medicine. It is now claimed to have health benefits to humans, including promoting lung and kidney health, anti-aging benefits, and antibacterial properties. Although these health benefits have not been conclusively proven, this rather unusual species is starting to be cultivated and processed for human consumption.

           This specimen was discovered by Mary Jane in the woods near the wildlife cut. The species of moth or butterfly that it is parasitizing is unknown.     

Hazel Galloway